Method and Apparatus for Synchronization of Proximate RFID Readers in a Gaming Environment

ABSTRACT

The present invention provides a system and method for an improved player tracking in a gaming environment. Certain embodiments include a plurality of radio frequency identification (RFID) readers for detecting a response signal from an RFID tag, an RFID tag generating a response signal including identification data in response to an interrogation signal transmitted by one of the plurality of RFID readers, and a location manager controlling transmission by the plurality of RFID readers according to at least one collision-avoidance scheme. The collision-avoidance scheme may include one or more of the following schemes: localized RFID reader managers coordinating electrical operation of the plurality of RFID readers, an active RFID reader transmitting the interrogation signal and a plurality of passive RFID readers listening for the response signal, an RFID reader multiplexed through a plurality of antennas, TDMA, CDMA, and/or quasi-random synchronization for the RFID readers, for example.

BACKGROUND OF THE INVENTION

The present invention generally relates to a gaming environment. Inparticular, the present invention relates to player tracking in a gamingenvironment.

Gaming machines, such as slot machines, fruit machines, or pokermachines, have in recent years become one of the more popular, exciting,and sophisticated wagering activities available at casinos and othergambling locations. At the same time, gaming machines have also become asource of greater revenue for gaming establishments. Thus, competitionbetween manufacturers of gaming machines has intensified as competitorsvie for business from gaming establishments. Additionally, gamingestablishments compete among themselves to attract regular and repeatcustomers.

A gaming machine providing entertaining and enticing features forplayers would be highly desirable to attract both new and returningplayers to a gaming establishment. One way to encourage returningplayers is a player tracking or player loyalty program at a gamingestablishment or network of related gaming establishments. Playerloyalty programs reward incentives to players based on criteria, such asa number of visits to a casino, a number of games played, or other suchcriteria. For example, loyalty points may be assigned based on acriterion and redeemed for rewards such as discounts, free food ordrink, lodging, transportation, entertainment, or other reward.

Being able to determine a location of certain players in a gamingestablishment would also be highly desirable. Player location may beused to provide management of a gaming establishment with information todirect employees to bring a player his or her usual drink, food, and/orloyalty rewards, for example.

Player tracking may be facilitated by a gaming machine and/or by areader, such as a card reader or a radio frequency identification (RFID)reader at or near the gaming machine. In some systems, for example, aplayer swipes his or her player card through a reader at a gamingmachine before playing a game at that machine. In other systems, forexample, an RFID reader detects an RFID tag embedded within a playercard.

In an RFID system, the RFID reader includes a microchip and an antennathat transmits electromagnetic waves in an area around the location ofthe reader. The RFID tag on the player card also includes a microchipand antenna. When the electromagnetic waves from the reader impact theantenna on the tag, a magnetic field is formed. The RFID tag may bepassive and draw power from the magnetic field to power the microchip.An active RFID tag is powered by a battery, for example. The microchipat the RFID tag modulates the waves received from the RFID reader andtransmits the modulated waves back to the reader. The reader convertsthe received waves into digital data identifying the tag. The reader maythen transmit data to a server to track player loyalty points and/orplayer location in a gaming establishment.

In gaming establishments utilizing RFID readers or similar systems,interference may result from multiple readers transmitting signals inclose proximity to one another. Additionally, interference may resultfrom multiple RFID tags responding to a single reader's transmission.Such interference may prevent scanning of a player's card or properaccumulation of player loyalty points. A malfunction or inaccuracy inthe player loyalty or tracking system negatively impacts repeatedcustomer business and positive reputation at a gaming establishment.Thus, accurate tracking of player loyalty points and/or player locationis highly desirable.

An RFID-based player tracking system may include a plurality of readersor receivers, such as RFID readers, a plurality of player identificationdevices, and a server that may track player location and/or loyaltypoints. RFID readers transmit an “interrogation” signal to activate RFIDtags in the vicinity of the reader. After transmission, the RFID readers“listen” or wait to receive response signals from RFID tags in responseto the interrogation signal. When an RFID reader receives a response,data conveyed by the response is relayed to the server for furtherprocessing. The server may use the data along with information regardingan identity and location of the RFID reader to determine a location ofthe RFID tag. The RFID tag may be associated with a particular playerprofile. Once the identity and location of the player are determined, anaction such as initiating a player loyalty session or special attractionmode on a nearby gaming machine may be activated by the server.Additionally, attention may be directed to the player at the location bythe gaming establishment.

RFID tags may be implemented as read-write devices, capable of receivingand storing information sent by a nearby RFID reader. Thus, the RFID tagmay be used to store information amount a player or holder, such asname, refreshment preferences, access level, and other information. Suchinformation stored at the RFID tag may then be accessible by RFIDreaders. Information transmitted between an RFID reader and an RFID tagmay be encrypted.

RFID readers may be integrated into gaming machines or other gamingsystems and/or positioned throughout the floor of the gamingestablishment (e.g., a casino). In a crowded environment with many RFIDreaders, RFID readers may interfere with each other through transmissionand/or receipt of signals. Interference, often referred to as readercollision, may occur when two or more RFID readers within range of eachother transmit interrogation signals at approximately the same time.Simultaneous transmission may result in erratic reading of RFID tags,reduced reading range, or even an inability to read tags.

Distance between RFID readers that exposes the readers to readercollision varies (from less than a foot to hundreds of feet, forexample) depending on factors such as transmitter power, receiversensitivity, RFID reader frequency, and physical characteristics oftransceiver antenna and RFID tags in the area. Environmental factors,such as metal structures that may conduct or reflect radio signals, mayalso influence a potential for mutual interference.

Systems, such as U.S. Patent Publication No. 2003/0036425A1 to Kaminkowet al, attempt to address reader collision in two primary ways: (1) byshaping an active volume of the RFID reader through use of shieldingaround RFID reader antenna and/or by varying transmitter power and (2)by using the location manager to control operation of the RFID readers.However, both methods have drawbacks.

Shaping the active volume of an RFID reader by shielding the RFID readerantenna may be somewhat effective in reducing the interference betweenthe RFID readers housed in adjacent gaming systems. However, shieldingdoes not reduce interference between RFID readers housed in gamingmachines that face each other from opposing banks of machines. Reducingthe power of the transmitters may help reduce interference to a limitedextent but also reduces an ability of an interrogation signal topenetrate to an RFID tag held in a wallet, purse or pocket, for example.Reducing power of transmitters to a point that eliminates readercollision may also create blind spots in a system's coverage of a gamingenvironment, such as a casino floor.

Additionally, the shielding material used to shape the active volume ofthe RFID reader may also have an undesirable effect of de-tuning theRFID antenna. De-tuning the antenna results in reduced performance ofthe RFID reader.

Current RFID readers operate autonomously with respect to each other andcommunicate only with a single, centralized location manager responsiblefor managing the operation of all RFID readers on a property. Such asystem may be managing the operation of hundreds or even thousands ofRFID readers, as well as processing data produced by the readers.Extensive management places a heavy burden on current tracking systems.Additionally, a complex network associated with current systems includesinherent delays that reduce responsiveness of the system and impair theability of the system to process a large number of RFID tags in a timelymanner.

Attempts have been made to overcome the difficulty in reading multipleRFID tags in a given area. In one method, a command response protocol isused to interrogate RFID tags with specific identities or groups ofidentities using a tree algorithm. However, this and other methods aresusceptible to blocking efforts, such as denial of service attacks byspecially built RFID tags, such as those developed by RSA Laboratories,that respond to all interrogations regardless of the identifier.

Therefore, a system and method that overcome the shortcomings associatedwith current systems would be highly desirable. A system and method thatimprove management of RFID devices in a gaming environment would behighly desirable. A system and method that help to avoid deliberateinterference, such as denial of service devices, would also be highlydesirable.

Thus, there is a need for an improved system and method forsynchronizing RFID readers in close proximity in a gaming environment.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a system and method for improved playertracking in a gaming environment. An embodiment of an improved playertracking system includes a plurality of radio frequency identification(RFID) readers for detecting a response signal from an RFID tag, an RFIDtag generating a response signal including identification data inresponse to an interrogation signal transmitted by one of the pluralityof RFID readers, and a location manager controlling transmission by theplurality of RFID readers according to at least one collision-avoidancescheme. The collision-avoidance scheme may include one or more of thefollowing schemes: localized RFID reader managers coordinatingelectrical operation of the plurality of RFID readers, an active RFIDreader transmitting the interrogation signal and a plurality of passiveRFID readers listening for the response signal, and an RFID readermultiplexed through a plurality of antennas. The collision-avoidancescheme also may include a time division multiple access (TDMA)synchronization scheme for the plurality of RFID readers, a carrierdetect multiple access (CDMA) synchronization scheme for the pluralityof RFID readers, and/or a quasi-random synchronization scheme for theplurality of RFID readers. In an embodiment, the collision-avoidancescheme includes active synchronization of RFID readers via at least oneof a wire-based protocol and a wireless network protocol.

In an embodiment, the plurality of RFID readers are positioned withrespect to a plurality of gaming machines. The location manager maytrack a location of the RFID tag based on information received from atleast one of the plurality of RFID readers. The location manager maycommunicate with a plurality of localized RFID reader managers tocontrol the plurality of RFID readers. In an embodiment, the RFID tag isincorporated into a card, badge, or other item such as a bracelet orring.

An embodiment of a method for synchronizing radio frequencyidentification readers located in close proximity in a gamingenvironment includes coordinating a plurality of RFID readers accordingto a synchronization scheme, transmitting an interrogation signalaccording to the synchronization scheme, and receiving a response signalgenerated in response to the interrogation signal. The response signalincludes identification information for an RFID tag. The synchronizationscheme includes at least one of the following: coordinating electricaloperation of the plurality of RFID readers using localized RFID readermanagers, transmitting the interrogation signal from an active RFIDreader and waiting for the response signal at a plurality of passiveRFID readers, multiplexing an RFID reader with a plurality of antennas,using TDMA to transmit the interrogation signal from one of theplurality of RFID readers, using CDMA to transmit the interrogationsignal from one of the plurality of RFID readers, and using aquasi-random synchronization scheme to transmit the interrogation signalfrom one of the plurality of RFID readers. The synchronization schememay also include active synchronization of the plurality of RFID readersvia at least one of a wire-based protocol and a wireless networkprotocol.

In an embodiment, the plurality of RFID readers are positioned withrespect to a plurality of gaming machines. A location of the RFID tagmay be tracked based on the identification information received from atleast one of the plurality of RFID readers. In an embodiment, a centrallocation manager controls the plurality of RFID readers.

An embodiment of a method for improved tracking in a gaming environmentincludes positioning a plurality of RFID readers in a gamingenvironment, coordinating the plurality of RFID readers according to acollision-avoidance scheme, transmitting an interrogation signalaccording to the collision-avoidance scheme, receiving a response signalgenerated in response to the interrogation signal, and tracking the RFIDtag in the gaming environment based on the identification information.The response signal includes identification information for an RFID tag.The collision-avoidance scheme includes at least one of coordinatingelectrical operation of the plurality of RFID readers using localizedRFID reader managers, transmitting the interrogation signal from anactive RFID reader and waiting for the response signal at a plurality ofpassive RFID readers, multiplexing an RFID reader with a plurality ofantennas, using TDMA to transmit the interrogation signal, using CDMA totransmit the interrogation signal, and using a quasi-randomsynchronization scheme to transmit the interrogation signal. Thecollision-avoidance scheme may also include active synchronization ofthe plurality of RFID readers via at least one of a wire-based protocoland a wireless network protocol.

In an embodiment, the method further includes positioning the pluralityof RFID readers with respect to a plurality of gaming machines. Themethod may also include tracking a location of the RFID tag based on theidentification information received from at least one of the pluralityof RFID readers. Additionally, the method may include associating theidentification information with a record. In an embodiment, location andactivity of a person, such as a player or employee, may be tracked usinginformation from the RFID tag and at least one of the plurality of RFIDreaders.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a player tracking system used in accordance with anembodiment of the present invention.

FIG. 2 illustrates a flow diagram for a method for radio frequencyidentification at random intervals in a gaming environment in accordancewith an embodiment of the present invention.

FIG. 3 illustrates a player tracking system including localized managersused in accordance with an embodiment of the present invention.

FIG. 4 illustrates a player tracking system utilizing an active RFIDreader with multiple passive RFID readers used in accordance with anembodiment of the present invention.

FIG. 5 illustrates a player tracking system that multiplexes a singleRFID reader through multiple antennas in accordance with an embodimentof the present invention.

FIG. 6 shows a flow diagram for a method for improved player tracking inaccordance with an embodiment of the present invention.

The foregoing summary, as well as the following detailed description ofcertain embodiments of the present invention, will be better understoodwhen read in conjunction with the appended drawings. For the purpose ofillustrating the invention, certain embodiments are shown in thedrawings. It should be understood, however, that the present inventionis not limited to the arrangements and instrumentality shown in theattached drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a player tracking system 100 used in accordance withan embodiment of the present invention. The system 100 includes aplurality of Radio Frequency Identification (RFID) readers 110, amanager 120, and at least one RFID tag 130. The readers 110 communicatewith the manager 120 via a wireless and/or wired connection.

In an embodiment, the RFID readers 110 include an antenna and amicrochip or processor. In an embodiment, the manager 120 includes aserver, a workstation, a handheld device, and/or other computing system.In an embodiment, the RFID tag 130 includes an antenna and a microchipor other processor. The RFID tag 130 may be incorporated into a badge,card, or accessory, such as bracelet or ring, for example.

In operation, the readers 110 transmit an interrogation signal to detectthe tag 130. The interrogation signal may be a radio frequency signal,an electromagnetic signal, a microwave signal, an infrared signal, orother communication signal, for example. If the tag 130 detects aninterrogation signal, either passively or actively, the tag 130generates a response identification signal that is transmitted back tothe reader 110. The reader 110 relays the information in theidentification signal to the manager 120. Thus, player identity, playerlocation relative to a reader 110, and other information may bedetermined and relayed to the manager 120, for example.

In an embodiment, the reader 110 may be incorporated into a gamingmachine or other gaming system or may be located separately from agaming machine or gaming system. For example, the reader 110 may be partof a gaming machine console or positioned on or adjacent to a gamingmachine or gaming system. As another example, the reader 110 may beintegrated into a button, handle, or other components of a gamingmachine, for example. In an embodiment, the RFID reader 110 may be ahandheld device.

In an embodiment, the RFID tag 130 includes an integrated circuit (forexample, a Microchip MCRF250 or other chip). The RFID readers 110interrogate by sending a “gap pulse.” The RFID tag 130 uses a randomnumber generator, such as an internal random number generator, todetermine a time delay. After the time delay has passed, the RFID tag130 transmits a reply to the RFID reader 110. Thus, RFID tags transmitresponses at different times without a specialized tag collisionavoidance algorithm in the RFID reader 110. Random response times alsohelp avoid denial of service and other attack techniques.

FIG. 2 illustrates a flow diagram for a method 200 for radio frequencyidentification at random intervals in a gaming environment in accordancewith an embodiment of the present invention. First, at step 210, aninterrogation signal is broadcast to identify nearby RFID tags. Then, atstep 220, the interrogation signal is detected. For example, an RFID tag130 detects the interrogation signal from an RFID reader 110.

Next, at step 230, a random response interval is determined. Forexample, a random number generator at the RFID tag 130 generates arandom number to determine a time delay before response by the RFID tag130. Then, at step 240, a response signal is transmitted after therandom response interval has passed. For example, after the random timedelay, the RFID tag 130 produces a response signal includingidentification information and transmits the response signal back to theRFID reader 110.

At step 250, the response signal is received. For example, the RFIDreader 110 antenna receives the response signal from the RFID tag 130.Finally, at step 260, data from the response signal is relayed to amanager 120. For example, the reader 110 transmits player identificationand location information to the manager 120 to facilitate playertracking.

Certain embodiments of the present invention provide solutions tominimize reader collision caused by multiple RFID readers withoverlapping active volumes. One or more techniques, as described furtherbelow, may be used in the system 100 to minimize reader collision andeffects of reader collision.

FIG. 3 illustrates a player tracking system 300 including localizedmanagers used in accordance with an embodiment of the present invention.The player tracking system 300 includes a plurality of RFID readers 310,a local manager 320, an RFID tag 330, and a location manager 340.

The plurality of RFID readers 310 are connected to the local manager 320through a wired or wireless network. The local manager 320 controlssynchronization and operation of the RFID readers 310. The RFID readers310 are also connected to the location manager 340 through a network,which may or may not be the same network as the network connecting RFIDreaders 310 to the local manager 320.

The RFID readers 310 send interrogation signals. The RFID tag 330receives an interrogation signal and sends a response signal. The RFIDreader(s) 310 receiving the response signal send data conveyed in theresponse signal to the location manager 340.

In the system 300, rather than using a single server to manageelectrical operation as well as collection and processing of data fromthe RFID readers 310, electrical operation of the RFID readers 310 iscontrolled by one or more localized managers 320. In an embodiment, thelocalized managers 320 do not collect or process data from the RFIDreaders 310. The local manager 320 focuses on coordinating theelectrical operation of the RFID readers 310 under the control of thelocal manager 320.

In an embodiment, localized RFID reader managers 320 are connected toand may communicate with other local managers 320. Thus, local managers320 may coordinate operations of adjacent groups of RFID readers 310,for example. In an embodiment, localized RFID reader managers 320 arealso connected to and may communicate with the centralized locationserver 340. The location manager 340 may serve as a central authorityfor RFID operations and configurations. The location manager 340 maycollect player and location data from the RFID readers 310 and processthe data for player tracking and other purposes, for example. In anembodiment, the tracking system 300 may also be used to track employeesof a gaming establishment.

FIG. 4 illustrates a player tracking system 400 utilizing an active RFIDreader with multiple passive RFID readers used in accordance with anembodiment of the present invention. The system 400 includes a pluralityof passive RFID readers 410, an active RFID reader 420, an RFID tag 430,and a location manager 440.

The plurality of passive RFID readers 410 are connected to the locationmanager 440 through a wired or wireless network. The active RFID reader420 is also connected to the location manager 440.

The active RFID reader 420 transmits an interrogation signal. The RFIDtag 430 receives the interrogation signal. The RFID tag 430 then sends aresponse signal that is received by RFID readers within receiving range,including both passive RFID readers 410 and active RFID reader 420. AllRFID readers 410, 420 receiving the response signal from the RFID tag430 convey the received data to the location manager 440.

In a dense RFID reader environment, such as a bank of electronic gamingmachines, use of a single active RFID reader 420 with multiple passiveRFID readers 410 may be beneficial as well as cost effective. In anembodiment, each gaming machine is outfitted with a passive RFID reader410 that is capable of receiving response signals from a RFID tag 430.The active RFID reader 420 is capable of sending interrogation signalsand receiving response signals. An active RFID reader 420 is positionedsuch that an active volume of the active RFID reader 420 covers a groupof passive RFID readers 410. In an embodiment, the active RFID readers420 in a gaming environment are positioned so that all of the passiveRFID readers 410 in the gaming environment are covered by an active RFIDreader. When the active RFID reader 420 transmits an interrogationsignal, all RFID readers 410, 420 in the area may receive the responsesfrom RFID tags 430 in the vicinity. The active RFID readers 420 may alsoemploy additional techniques to avoid reader collision with other nearbyactive RFID readers.

FIG. 5 illustrates a player tracking system 500 that multiplexes asingle RFID reader through multiple antennas in accordance with anembodiment of the present invention. The system 500 includes a pluralityof antennas 510, a multiplexer 520, an RFID reader 525, an RFID tag 530,and a location manager 540.

The RFID reader 525 is connected to a plurality of antennas 510 throughthe multiplexer 520. The multiplexer 520 switches between antennas 510.In an embodiment, the multiplexer 520 switches between antennas 510 on arotating basis, for example. When a response signal from RFID tag 530 isreceived, data conveyed by the signal, as well as information related tothe antenna 510 that is active at the time of reception, is sent to thelocation manager 540.

In an embodiment, a single RFID reader 525 may be multiplexed through aplurality of antennas 510 positioned at different locations. Forexample, an antenna 510 may be placed in several electronic gamingmachines. The multiplexing circuitry 520 allows one antenna 510 totransmit at any given time.

In an embodiment, the multiplexer 520 and/or location manager 540 pollthe antennas 510. An antenna 510 may execute a complete transmit andreceive cycle before the multiplexer 520 switches to another antenna510.

In another embodiment, time division multiple access (TDMA) may be usedto reduce reader collision. RFID readers in a given area aresynchronized to a common time base. For example, a local or locationmanager or other computer transmits a timing signal to synchronize theRFID readers. The RFID readers are programmed to operate at differentoffsets from a base time unit (each half second, for example). That is,a manager or other computer system assigns different time slots toreaders. A reader transmits in a given time slot and receives responsesignals at any time slot. Use of different offsets helps to ensure thatthe readers do not transmit at the same time.

In another embodiment, carrier detect multiple access (CDMA) or carriersense multiple access (CSMA) may be used to reduce reader collision.Prior to transmitting an interrogation signal, an RFID reader checks fora presence of a carrier indicating another nearby RFID reader istransmitting an interrogation signal. If a carrier is detected, the RFIDreader delays for a period of time, such as a fixed or random period oftime. After the period of time has elapsed, the reader again checks forthe presence of a carrier. When a carrier is no longer detected, theRFID reader sends an interrogation signal.

In an embodiment, RFID readers may be synchronized via wire- orwireless-based modes. For example, RFID readers communicate with eachother and coordinate operations through a wire-based protocol, such asRS-485. As another example, RFID readers communicate with each other andcoordinate operations through a wireless network or other wirelesscommunications mode (for example, infrared). Readers synchronize witheach other as they operate. A scheme or protocol, such as a wired,wireless (e.g., 802.11), or infrared scheme, may be used to synchronizereader transmission. Furthermore, RFID readers may operate in aquasi-random fashion, such as that described in U.S. Pat. No. 6,566,997,which is herein incorporated by reference.

A manager or computer receives data from RFID readers in accordance toone or more of the above-described embodiments. The data includes anRFID tag identification number, RFID reader identification number,direction, distance, and/or timing information, for example. The datamay be used to identify a patron from a database. The data may be usedto determine the patron or employee's location in a gamingestablishment. For a more accurate position, location data may betriangulated from multiple RFID readers.

FIG. 6 shows a flow diagram for a method 600 for improved playertracking in accordance with an embodiment of the present invention.First, at step 610, RFID readers are positioned in a gamingestablishment. For example, RFID readers may be positioned on orincorporated in electronic gaming machines in a casino. Next, at step620, operation of the readers and one or more manager systems iscoordinated using one or more of the communication techniques describedabove. For example, localized RFID reader managers and a centrallocation manager may be used with RFID readers operating using a TDMAtransmission scheme to detect RFID tags in a casino. Then, at step 630,one or more interrogation signals are transmitted by one or more RFIDreaders. For example, the RFID readers at the gaming machines transmitinterrogation signals according to their time slots to detect RFID tags.

At step 640, a response signal is received from an RFID tag. Forexample, at least one RFID reader in a vicinity to the RFID tag receivesthe response signal generated by the RFID tag in response to theinterrogation signal(s). Next, at step 650, data conveyed in theresponse signal is relayed to a local or central manager system. TheRFID reader(s) extract data from the response signal and relay the datato the central location manager. Then, at step 660, the RFID tag (andthe player or employee associated with the tag) is tracked by themanager system or central authority. For example, the data from the RFIDtag and RFID reader(s) may be used to determine a location of the RFIDtag (e.g., through triangulation from multiple readers or locationinformation for a single reader) and/or monitor activities of a bearerof the RFID tag.

Thus, certain embodiments provide one or more methods for RFID readermanagement and reduction in reader collision. Reduction in readercollision and other interference provides improved player tracking,player loyalty programs, employee tracking, and casino management.Various embodiments may be used alone or in various combinations.

Improved player tracking allows attention to be paid to recurringcustomers, as well as new customers. Improved player tracking allowstraffic patterns to be analyzed in a gaming environment to identifyactive and idle areas. Improved player tracking allows a gaming systemor operator to trigger a gaming machine or bank of gaming machines toactivate a certain attract mode, indicator, and/or gaming mode, forexample, based on the player located nearby. Improved employee trackinghelps preserve security and responsibility in a gaming environment.

While the invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from its scope.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed, but that the invention will include allembodiments falling within the scope of the appended claims.

1-20. (canceled)
 21. An improved player tracking system for a gamingenvironment, said system comprising: a plurality of radio frequencyidentification (RFID) readers positioned in the gaming environment fordetecting a response signal from an RFID tag; an RFID tag generating aresponse signal including identification data in response to aninterrogation signal transmitted by one of said plurality of RFIDreaders, said RFID tag and identification data identifying a player; anda location manager controlling transmission by said plurality of RFIDreaders according to at least one reader collision-avoidance scheme. 22.The system of claim 21, wherein said at least one readercollision-avoidance scheme further includes at least one of: localizedRFID reader managers coordinating electrical operation of said pluralityof RFID readers; an active RFID reader transmitting said interrogationsignal and a plurality of passive RFID readers listening for saidresponse signal; and an RFID reader multiplexed through a plurality ofantennas.
 23. The system of claim 21, wherein said at least one readercollision-avoidance scheme further includes a carrier sense multipleaccess (CSMA) synchronization scheme for said plurality of RFID readers.24. The system of claim 21, wherein said location manager communicateswith a plurality of localized RFID reader managers to control saidplurality of RFID readers.
 25. An improved player tracking system for agaming environment, said system comprising: a plurality of radiofrequency identification (RFID) readers positioned in the gamingenvironment, each of the plurality of RFID readers adapted to transmitan interrogation signal according to a reader collision-avoidance schemeand to receive a response signal generated in response to theinterrogation signal, wherein the response signal comprisesidentification information for an RFID tag, the RFID tag identifying aplayer; and a location manager adapted to coordinate said plurality ofRFID readers according to the reader collision-avoidance scheme.
 26. Thesystem of claim 25, wherein the location manager is adapted to track theRFID tag in the gaming environment based on the identificationinformation.
 27. The system of claim 25, wherein said at least onereader collision-avoidance scheme further includes at least one of:localized RFID reader managers coordinating electrical operation of saidplurality of RFID readers; an active RFID reader transmitting saidinterrogation signal and a plurality of passive RFID readers listeningfor said response signal; and an RFID reader multiplexed through aplurality of antennas.
 28. The system of claim 25, wherein said at leastone reader collision-avoidance scheme further includes a carrier sensemultiple access (CSMA) synchronization scheme for said plurality of RFIDreaders.
 29. The system of claim 25, wherein said location managercommunicates with a plurality of localized RFID reader managers tocontrol said plurality of RFID readers.
 30. A player tracking system,the system comprising: a plurality of radio frequency identification(RFID) readers positioned in a gaming environment, wherein each of theplurality of RFID readers is adapted to receive a response signalgenerated in response to an interrogation signal, wherein the responsesignal comprises identification information for an RFID tag identifyinga player; a local manager in communication with the plurality of RFIDreaders, wherein the local manager is adapted to manage the electricaloperation of the RFID readers according to a reader collision-avoidancescheme; and a location manager in communication with the RFID readers,wherein the location manager is adapted process the response signal. 31.The system of claim 31, wherein the local manager and the locationmanager communicate with the RFID readers over the same network.
 32. Thesystem of claim 31, further including a second local manager, whereinthe local manager and the second local manager are adapted to coordinateoperations of adjacent groups of RFID readers.
 33. The system of claim31, wherein the location manager is adapted to process the responsesignal to track the player.
 34. A player tracking system, the systemcomprising: a plurality of passive radio frequency identification (RFID)readers positioned in a gaming environment, wherein each of theplurality of passive RFID readers is adapted to receive a responsesignal generated in response to an interrogation signal, wherein theresponse signal comprises identification information for an RFID tagidentifying a player; an active RFID reader positioned in the gamingenvironment, wherein the active RFID reader is adapted to receive theresponse signal from the RFID tag, wherein the active RFID reader isadapted to transmit the interrogation signal; and a location manager incommunication with the plurality of passive RFID readers and the activeRFID reader, wherein the location manager is adapted to process areceived response signal.
 35. The system of claim 34, wherein theplurality of passive RFID readers is located in a bank of electronicgaming machines.
 36. The system of claim 35, wherein the active RFIDreader is located in the bank of electronic gaming machines.
 37. Thesystem of claim 34, wherein the active RFID reader is positioned suchthat an active volume of the active RFID reader covers the plurality ofpassive RFID readers.
 38. The system of claim 34, further including asecond active RFID reader, wherein the active RFID reader and the secondactive RFID reader are adapted to transmit the interrogation signalaccording to a reader collision-avoidance scheme.
 39. The system ofclaim 34, wherein the location manager is adapted to process theresponse signal to track the player.
 40. A player tracking system, thesystem comprising: a plurality of antennas positioned in a gamingenvironment, wherein each antenna in the plurality of antennas isadapted to receive a response signal generated in response to aninterrogation signal, wherein the response signal comprisesidentification information for a radio frequency identification (RFID)tag identifying a player; a multiplexer in communication with theplurality of antennas, wherein the multiplexer is adapted to switchbetween one or more of the plurality of antennas; an RFID reader incommunication with the plurality of antennas through the multiplexer,wherein the RFID reader is adapted to transmit the interrogation signalusing at least one antenna in the plurality of antennas through themultiplexer; and a location manager in communication with the RFIDreader, wherein the location manager is adapted to process the responsesignal.
 41. The system of claim 40, wherein the multiplexer is adaptedto switch on a rotating basis.
 42. The system of claim 40, wherein themultiplexer is adapted to switch after a complete transmit and receivecycle.
 43. The system of claim 40, wherein the RFID reader is adapted tocommunicate the response signal and an identifier of the antenna thatreceived the response signal to the location manager.
 44. The system ofclaim 40, wherein the location manager is adapted to process theresponse signal to track the player.
 45. A method for improved playertracking in a gaming environment, said method comprising: coordinating aplurality of radio frequency identification (RFID) readers positioned ina gaming environment to transmit a plurality of interrogation signalsaccording to a reader collision-avoidance scheme; and tracking at leastone RFID tag in said gaming environment based on a response by said RFIDtag to at least one of said plurality of interrogation signals, saidRFID tag identifying a player.